Dental screwdriver

Abstract

A shaft for a dental screwdriver configured to be inserted into a bore cavity of a dental prosthetic. The shaft has a drive tip for driving a dental screw used to fix the dental prosthetic to the dental implant when the shaft is inserted into the bore cavity of the dental prosthetic. The drive tip is made of a shape memory smart alloy. The shaft also has an axial shaft portion made of a shape memory smart alloy with different material characteristics than the shape memory smart alloy of the drive tip. The axial shaft portion is configured to elastically bend from an original shape to a bent shape along the axial shaft portion without imparting a bending action and torqueing forces along the drive tip when the dental screwdriver is inserted into the bore cavity of the dental prosthetic.

What is claimed is: 
     
         1 . A shaft for a dental screwdriver configured to be inserted into a bore cavity of a dental prosthetic, the shaft comprising:
 a drive tip for driving a dental screw used to fix the dental prosthetic to the dental implant when the shaft is inserted into the bore cavity of the dental prosthetic, the drive tip being made of a shape memory smart alloy; and   an axial shaft portion made of a shape memory smart alloy with different material characteristics than the shape memory smart alloy of the drive tip, the axial shaft portion being configured to elastically bend from an original shape to a bent shape along the axial shaft portion without imparting a bending action and torqueing forces along the drive tip when the dental screwdriver is inserted into the bore cavity of the dental prosthetic.   
     
     
         2 . The shaft of  claim 1 , wherein the shape memory smart alloy of each of the axial shaft portion and the drive tip is nickel titanium alloy. 
     
     
         3 . The shaft of  claim 1 , wherein the axial shaft portion is formed in one piece with the drive tip. 
     
     
         4 . The shaft of  claim 1 , wherein the axial shaft portion and the drive tip are configured to travel through curved and straight spaces in the bore cavity of the dental prosthetic to reach the dental screw used to fix the dental prosthetic to the dental implant. 
     
     
         5 . The shaft of  claim 1 , wherein the axial shaft portion is further configured to elastically return to the original shape from the bent shape. 
     
     
         6 . A dental screwdriver having the shaft of  claim 1 . 
     
     
         7 . The dental screwdriver of  claim 6 , wherein the shape memory smart alloy of each of the axial shaft portion and the drive tip of the shaft is nickel titanium alloy. 
     
     
         8 . A shaft for a dental screwdriver configured to be inserted into a bore cavity of a dental prosthetic, the shaft comprising:
 a front end portion;   a rear end portion opposite the front end portion;   an axial shaft portion made of a shape memory smart alloy and disposed between the front and rear end portions, the axial shaft portion being configured to elastically bend from an original shape to a bent shape along the axial shaft portion without imparting a bending action and torqueing forces along the front and rear end portions when the dental screwdriver is inserted into the bore cavity of the dental prosthetic; and   a drive tip disposed at the front end portion for driving a dental screw used to fix the dental prosthetic to a dental implant when the dental screwdriver is inserted into the bore cavity of the dental prosthetic, the drive tip being made of a shape memory smart alloy with different material characteristics than the shape memory smart alloy of the axial shaft portion.   
     
     
         9 . The shaft of  claim 8 , wherein the axial shaft portion is further configured to elastically return to the original shape from the bent shape. 
     
     
         10 . The shaft of  claim 9 , wherein the shaft is configured such that a substantially linear curvature is maintained near and along the front end portion when the axial shaft portion elastically bends from the original shape to the bent shape and elastically returns towards the original shape from the bent shape to allow coupling of the drive tip to the dental screw when the shaft is inserted into the bore cavity of the dental prosthetic. 
     
     
         11 . The shaft of  claim 8 , wherein the front end portion is less elastic than the axial shaft portion. 
     
     
         12 . The shaft of  claim 8 , wherein the axial shaft portion is formed in one piece with both the front end portion and the drive tip. 
     
     
         13 . The shaft of  claim 8 , wherein the axial shaft portion and the drive tip are configured to travel through curved and straight spaces in the bore cavity of the dental prosthetic to reach the dental screw used to fix the dental prosthetic to the dental implant. 
     
     
         14 . The shaft of  claim 8 , wherein the shape memory smart alloy of each of the axial shaft portion and the drive tip is nickel titanium alloy. 
     
     
         15 . A dental screwdriver having the shaft of  claim 14 . 
     
     
         16 . A dental screwdriver having the shaft of  claim 8 .